Wednesday, June 6, 2012

FreeBSD, Netflix, CDN

You could say "Netflix chose FreeBSD because they can keep their changes proprietary." Sure, they could. But they're not making appliances that they're selling - they're owning the infrastructure and servers. It's unclear whether they'd have to contribute back any Linux changes if they ran Linux on their open connect platform. They're making a conscious, public decision to distribute their changes back to FreeBSD - even though they don't have to.

You could say "Netflix chose FreeBSD because the people inside the company knew FreeBSD." Sure, they may have. The same thing could be said about why start-ups and tech companies choose Linux. A lot of the time its because they're chasing enterprise support from Redhat. But technology startups using Ubuntu or Debian tend not to be paying support fees - they hire smart people who know the technology. So, yes - "using what they know."

According to the Netflix Openconnect website:

"This was selected for its balance of stability and features, a strong development community and staff expertise. We will contribute changes we make as part of our project to the community through the FreeBSD committers on our team."

Let's pull this apart a little.

"Balance of stability and features." FreeBSD has long been derided for how slowly it moves in some areas. The FreeBSD developers tend to be a conservative bunch, trying to find the balance between new feature development and maintaining both stability and backwards compatibility.

"Strong community." FreeBSD has a strong technical development community and Netflix finds this very important. They're also willing to join and participate in the community like many other companies do.

"Staff expertise." So yes, their staff are familiar with FreeBSD. They're also familiar with Linux. They chose a platform which they have the expertise to develop, use and improve. They didn't just choose an unfamiliar platform because of marketing brochures or sales promises. I don't see any negatives here. I'm sure that Google engineers chose Linux to begin with because they were familiar with Linux.

"Contribute changes we make as part of our project to the community." Netflix has committed to push improvements and fixes back to the upstream project They contributed some bug fixes in the 10GE Intel driver and IPv6 stack this week. This is collaborative open source working the way it should.

Why would Netflix push back changes and improvements into a project when they're not required to? That's something you should likely ask them. But the same good practice arguments hold for both Linux AND BSD projects:

The project is a constantly moving target. If you don't push your changes back upstream, you risk carrying around increasingly larger changes as your project and your BSD upstream project diverge. This will just make things more difficult in the long run.

By pushing your changes upstream, you make it easier to move with the project - including adopting improvements and new features. If you keep large changes to yourself, you will likely find it increasingly difficult to update your software to the newer upstream versions. And that upstream project is likely adding bug fixes, improvements and new features - which at some point you may wish to leverage. By pushing your changes upstream, you make it a lot easier to move to future versions of the upstream project, allowing you to leverage all those fixes and improvements without too much engineering time.

By participating, you encourage others to adopt your technology. By pushing your changes and improvements upstream, you decrease the amount of software you have to maintain yourself (and keep patching as the upstream project moves along.) But you also start to foster technology adoption. The FreeBSD jail project started out of the desire by a hosting company to support virtualisation. Since then, the Jail infrastructure has been adopted by many other companies and individuals.

When others use your technology, they also find and fix bugs in your technology; they may even improve it. The FreeBSD jail support has been extended to include IPv6 support, shared memory support and integrates into the VIMAGE (virtualised networking) stack (which, by the way, came from Ironport/Cisco.) As a company, you may find that the community will do quite a lot of the work that you would normally have to hire engineers to do yourself. This saves time and saves money.

When companies contribute upstream, it encourages other companies to also contribute upstream. A common issue is "reinventing the wheel", where companies end up having to reinvent the same technology privately because no-one has contributed it upstream. They solve the same problems, they implement the same new features .. and they all spend engineering time and resources to do so.

And when companies contribute upstream, it encourages (private) developers to contribute. Open source developers love to see their code out there in the wild, in places they never quite thought of. It's encouraging to see companies build products with their code and contribute back bug fixes and improvements. It fosters a sense of community and participation, of "give and take", rather than just "take". This is exactly the kind of thing that keeps developers coming back to contribute more - and it attracts new developers. Honestly, who wouldn't want to say that some popular device is running code that they wrote in their spare time?

So, you could rant and rave about the conspiracy side of Linux versus FreeBSD. You could rant on about GPL versus BSD. Or, you could see the more useful side of things. You could see a large company who didn't have to participate at all, agreeing to contribute back their improvements to an open source operating system. You could see that by doing so, the entire open source ecosystem benefits - not just FreeBSD. There's nothing stopping Linux or other BSD projects from keeping an eye on the improvements made by Netflix and incorporating those improvements into their own project. And it's another case of a company participating and engaging the open source community - and having that community engage them right back.

As long as Netflix is sure that the changes they are pushing upstream will not be the backbone of their money making infrastructure (something that another giant can use out of the box to create a competitive product), there is no harm in them sharing their changes.